1. Field of Invention
The present invention pertains to the field of electronic systems. More particularly, this invention relates to approximating signal power and noise power in a system.
2. Art Background
A useful function in an electronic system is the determination of signal power and noise power. A determination of signal power and noise power may be used to determine signal-to-noise ratio (SNR) for an electronic system. For example, a determination of SNR in a communication system may be useful for characterizing the quality of a communication channel. In addition, an SNR determination may be useful for determining whether a receiving station is obtaining reliable data in the face of communication channel noise.
The signal in a communication system commonly includes an in-phase component and a quadrature component. The in-phase and quadrature components are typically represented by a complex signal. A complex signal usually has a real part that represents the in-phase component of the signal and imaginary part that represents the quadrature component of the signal. A signal power determination usually involves the calculation of squared terms for both the real and imaginary parts of the complex signal. Similarly, a noise power determination typically involves the calculation of squared terms for both the real and imaginary parts of the complex noise. Typically, such squared terms are calculated using one or more multipliers.
Unfortunately, the multipliers employed to calculate the squared terms for signal power and noise power typically require a relatively large area of integrated circuit die space to implement. This is the case particularly for high speed systems in which large numbers of gates are typically used to implement a multiplier. Such large areas of die space usually increase the cost of integration circuit fabrication and increase the overall costs of electronic systems that make use of signal-to-noise ratio determinations.